U.S. stocks rose on Monday as fears of an escalating conflict in Syria eased for the moment, while some of the biggest U.S. companies reported strong quarterly results.

The Dow Jones industrial average gained 212.90 points to close at 24,573.04, with Merck helping lead the gains in the index. The S&P 500 climbed 0.8 percent to 2,677.84, with materials and telecommunications as the best-performing sectors. The Nasdaq composite advanced 0.7 percent to 7,156.28.

Last week, the U.S. military conducted precision missile strikes against the Syrian government in response to a chemical attack carried out in the country. The attack was conducted in conjunction with France and the U.K.

The Pentagon described the U.S.-led strikes as a "justified, legitimate and proportionate response" to the Syrian regime's continued use of chemical weapons. Secretary of Defense James Mattis called the strikes a "one time shot" and said that they were aimed at Syrian government's chemical weapons infrastructure.

"You've also got so much coming out of Washington that makes investors nervous, but not panic unless it's an immediate threat," said Bruce McCain, chief investment strategist at Key Private Bank.

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Traders work on the floor of the New York Stock Exchange on January 31, 2014 in New York City

J.B Hunt Transport rose more than 6 percent on the back of a stronger-than-expected quarterly revenue, led by a 14 percent jump in Intermodal sales, its largest segment. The stock was the best-performing stock in both the S&P 500 and Dow industrials.

The earnings season is off to a good start thus far. Last week, BlackRock, J.P. Morgan Chase and Citigroup reported better-than-expected earnings. Netflix is scheduled to release its quarterly results Monday after the close.

Wall Street has high expectations for this earnings season, with analysts expecting a 17.3 percent increase in first-quarter earnings, according to FactSet.

"This represents a high bar for stocks to get over and [the] pattern of the past 20 years is that stocks have tended to struggle when upside earnings surprises have slowed," said Bruce Bittles, chief investment strategist at Baird. "Elevated earnings expectations are coming with stock market valuations stretched."